content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2012, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
   * Other names may be trademarks of their respective owners.]
   *
   * ----------
   * Month.java
   * ----------
   * (C) Copyright 2001-2009, by Object Refinery Limited and Contributors.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   Chris Boek;
   *
   * Changes
   * -------
   * 11-Oct-2001 : Version 1 (DG);
   * 14-Nov-2001 : Added method to get year as primitive (DG);
   *               Override for toString() method (DG);
   * 18-Dec-2001 : Changed order of parameters in constructor (DG);
   * 19-Dec-2001 : Added a new constructor as suggested by Paul English (DG);
   * 29-Jan-2002 : Worked on the parseMonth() method (DG);
   * 14-Feb-2002 : Fixed bugs in the Month constructors (DG);
   * 26-Feb-2002 : Changed getStart(), getMiddle() and getEnd() methods to
   *               evaluate with reference to a particular time zone (DG);
   * 19-Mar-2002 : Changed API for TimePeriod classes (DG);
   * 10-Sep-2002 : Added getSerialIndex() method (DG);
   * 04-Oct-2002 : Fixed errors reported by Checkstyle (DG);
   * 10-Jan-2003 : Changed base class and method names (DG);
   * 13-Mar-2003 : Moved to com.jrefinery.data.time package, and implemented
   *               Serializable (DG);
   * 21-Oct-2003 : Added hashCode() method (DG);
   * 01-Nov-2005 : Fixed bug 1345383 (argument check in constructor) (DG);
   * ------------- JFREECHART 1.0.x ---------------------------------------------
   * 05-Oct-2006 : Updated API docs (DG);
   * 06-Oct-2006 : Refactored to cache first and last millisecond values (DG);
   * 04-Apr-2007 : Fixed bug in Month(Date, TimeZone) constructor (CB);
   * 01-Sep-2008 : Added clarification for previous() and next() methods (DG);
   * 16-Sep-2008 : Deprecated DEFAULT_TIME_ZONE, and updated parsing to handle
   *               extended range in Year (DG);
   * 25-Nov-2008 : Added new constructor with Locale (DG);
   * 04-Feb-2009 : Fix for new constructor with Locale - bug 2564636 (DG);
   *
   */
  
  package org.jfree.data.time;
  
  import org.jfree.chart.date.MonthConstants;
  import org.jfree.chart.date.SerialDate;
  
  import java.io.Serializable;
  import java.util.Calendar;
  import java.util.Date;
  import java.util.Locale;
  import java.util.TimeZone;
  
  /**
   * Represents a single month.  This class is immutable, which is a requirement
   * for all {@link RegularTimePeriod} subclasses.
   */
  public class Month extends RegularTimePeriod implements Serializable {
  
      /** For serialization. */
      private static final long serialVersionUID = -5090216912548722570L;
  
      /** The month (1-12). */
      private int month;
  
      /** The year in which the month falls. */
      private int year;
  
      /** The first millisecond. */
      private long firstMillisecond;
  
      /** The last millisecond. */
      private long lastMillisecond;
  
      /**
       * Constructs a new Month, based on the current system time.
       */
      public Month() {
          this(new Date());
      }
  
      /**
       * Constructs a new month instance.
       *
       * @param month  the month (in the range 1 to 12).
       * @param year  the year.
       */
      public Month(int month, int year) {
          if ((month < 1) || (month > 12)) {
              throw new IllegalArgumentException("Month outside valid range.");
          }
          this.month = month;
          this.year = year;
          peg(Calendar.getInstance());
      }
  
      /**
       * Constructs a new month instance.
       *
       * @param month  the month (in the range 1 to 12).
       * @param year  the year.
       */
      public Month(int month, Year year) {
          if ((month < 1) || (month > 12)) {
              throw new IllegalArgumentException("Month outside valid range.");
          }
          this.month = month;
          this.year = year.getYear();
          peg(Calendar.getInstance());
      }
  
      /**
       * Constructs a new <code>Month</code> instance, based on a date/time and
       * the default time zone.
       *
       * @param time  the date/time (<code>null</code> not permitted).
       *
       * @see #Month(Date, TimeZone)
       */
      public Month(Date time) {
          this(time, TimeZone.getDefault(), Locale.getDefault());
      }
  
      /**
       * Creates a new <code>Month</code> instance, based on the specified time,
       * zone and locale.
       *
       * @param time  the current time.
       * @param zone  the time zone.
       * @param locale  the locale.
       *
       * @since 1.0.12
       */
      public Month(Date time, TimeZone zone, Locale locale) {
          Calendar calendar = Calendar.getInstance(zone, locale);
          calendar.setTime(time);
          this.month = calendar.get(Calendar.MONTH) + 1;
          this.year = calendar.get(Calendar.YEAR);
          peg(calendar);
      }
  
      /**
       * Returns the year in which the month falls.
       *
       * @return The year in which the month falls (as a Year object).
       */
      public Year getYear() {
          return new Year(this.year);
      }
  
      /**
       * Returns the year in which the month falls.
       *
       * @return The year in which the month falls (as an int).
       */
      public int getYearValue() {
          return this.year;
      }
  
      /**
       * Returns the month.  Note that 1=JAN, 2=FEB, ...
       *
       * @return The month.
       */
      public int getMonth() {
          return this.month;
      }
  
      /**
       * Returns the first millisecond of the month.  This will be determined
       * relative to the time zone specified in the constructor, or in the
       * calendar instance passed in the most recent call to the
       * {@link #peg(Calendar)} method.
       *
       * @return The first millisecond of the month.
       *
       * @see #getLastMillisecond()
       */
      @Override
      public long getFirstMillisecond() {
          return this.firstMillisecond;
      }
  
      /**
       * Returns the last millisecond of the month.  This will be
       * determined relative to the time zone specified in the constructor, or
       * in the calendar instance passed in the most recent call to the
       * {@link #peg(Calendar)} method.
       *
       * @return The last millisecond of the month.
       *
       * @see #getFirstMillisecond()
       */
      @Override
      public long getLastMillisecond() {
          return this.lastMillisecond;
      }
  
      /**
       * Recalculates the start date/time and end date/time for this time period
       * relative to the supplied calendar (which incorporates a time zone).
       *
       * @param calendar  the calendar (<code>null</code> not permitted).
       *
       * @since 1.0.3
       */
      @Override
      public void peg(Calendar calendar) {
          this.firstMillisecond = getFirstMillisecond(calendar);
          this.lastMillisecond = getLastMillisecond(calendar);
      }
  
      /**
       * Returns the month preceding this one.  Note that the returned
       * {@link Month} is "pegged" using the default time-zone, irrespective of
       * the time-zone used to peg of the current month (which is not recorded
       * anywhere).  See the {@link #peg(Calendar)} method.
       *
       * @return The month preceding this one.
       */
      @Override
      public RegularTimePeriod previous() {
          Month result;
          if (this.month != MonthConstants.JANUARY) {
              result = new Month(this.month - 1, this.year);
          }
          else {
              if (this.year > 1900) {
                  result = new Month(MonthConstants.DECEMBER, this.year - 1);
              }
              else {
                  result = null;
              }
          }
          return result;
      }
  
      /**
       * Returns the month following this one.  Note that the returned
       * {@link Month} is "pegged" using the default time-zone, irrespective of
       * the time-zone used to peg of the current month (which is not recorded
       * anywhere).  See the {@link #peg(Calendar)} method.
       *
       * @return The month following this one.
       */
      @Override
      public RegularTimePeriod next() {
          Month result;
          if (this.month != MonthConstants.DECEMBER) {
              result = new Month(this.month + 1, this.year);
          }
          else {
              if (this.year < 9999) {
                  result = new Month(MonthConstants.JANUARY, this.year + 1);
              }
              else {
                  result = null;
              }
          }
          return result;
      }
  
      /**
       * Returns a serial index number for the month.
       *
       * @return The serial index number.
       */
      @Override
      public long getSerialIndex() {
          return this.year * 12L + this.month;
      }
  
      /**
       * Returns a string representing the month (e.g. "January 2002").
       * <P>
       * To do: look at internationalisation.
       *
       * @return A string representing the month.
       */
      @Override
      public String toString() {
          return SerialDate.monthCodeToString(this.month) + " " + this.year;
      }
  
      /**
       * Tests the equality of this Month object to an arbitrary object.
       * Returns true if the target is a Month instance representing the same
       * month as this object.  In all other cases, returns false.
       *
       * @param obj  the object (<code>null</code> permitted).
       *
       * @return <code>true</code> if month and year of this and object are the
       *         same.
       */
      @Override
      public boolean equals(Object obj) {
          if (obj == this) {
              return true;
          }
          if (!(obj instanceof Month)) {
              return false;
          }
          Month that = (Month) obj;
          if (this.month != that.month) {
              return false;
          }
          if (this.year != that.year) {
              return false;
          }
          return true;
      }
  
      /**
       * Returns a hash code for this object instance.  The approach described by
       * Joshua Bloch in "Effective Java" has been used here:
       * <p>
       * <code>http://developer.java.sun.com/developer/Books/effectivejava
       * /Chapter3.pdf</code>
       *
       * @return A hash code.
       */
      @Override
      public int hashCode() {
          int result = 17;
          result = 37 * result + this.month;
          result = 37 * result + this.year;
          return result;
      }
  
      /**
       * Returns an integer indicating the order of this Month object relative to
       * the specified
       * object: negative == before, zero == same, positive == after.
       *
       * @param o1  the object to compare.
       *
       * @return negative == before, zero == same, positive == after.
       */
      @Override
      public int compareTo(TimePeriod o1) {
  
          int result;
  
          // CASE 1 : Comparing to another Month object
          // --------------------------------------------
          if (o1 instanceof Month) {
              Month m = (Month) o1;
              result = this.year - m.getYearValue();
              if (result == 0) {
                  result = this.month - m.getMonth();
              }
          }
  
          // CASE 2 : Comparing to another TimePeriod object
          // -----------------------------------------------
          else {
              // more difficult case - evaluate later...
              result = 0;
          }
  
          return result;
  
      }
  
      /**
       * Returns the first millisecond of the month, evaluated using the supplied
       * calendar (which determines the time zone).
       *
       * @param calendar  the calendar (<code>null</code> not permitted).
       *
       * @return The first millisecond of the month.
       *
       * @throws NullPointerException if <code>calendar</code> is
       *     <code>null</code>.
       */
      @Override
      public long getFirstMillisecond(Calendar calendar) {
          calendar.set(this.year, this.month - 1, 1, 0, 0, 0);
          calendar.set(Calendar.MILLISECOND, 0);
          return calendar.getTimeInMillis();
      }
  
      /**
       * Returns the last millisecond of the month, evaluated using the supplied
       * calendar (which determines the time zone).
       *
       * @param calendar  the calendar (<code>null</code> not permitted).
       *
       * @return The last millisecond of the month.
       *
       * @throws NullPointerException if <code>calendar</code> is
       *     <code>null</code>.
       */
      @Override
      public long getLastMillisecond(Calendar calendar) {
          int eom = SerialDate.lastDayOfMonth(this.month, this.year);
          calendar.set(this.year, this.month - 1, eom, 23, 59, 59);
          calendar.set(Calendar.MILLISECOND, 999);
          return calendar.getTimeInMillis();
      }
  
      /**
       * Parses the string argument as a month.  This method is required to
       * accept the format "YYYY-MM".  It will also accept "MM-YYYY". Anything
       * else, at the moment, is a bonus.
       *
       * @param s  the string to parse (<code>null</code> permitted).
       *
       * @return <code>null</code> if the string is not parseable, the month
       *         otherwise.
       */
      public static Month parseMonth(String s) {
          Month result = null;
          if (s == null) {
              return result;
          }
          // trim whitespace from either end of the string
          s = s.trim();
          int i = Month.findSeparator(s);
          String s1, s2;
          boolean yearIsFirst;
          // if there is no separator, we assume the first four characters
          // are YYYY
          if (i == -1) {
              yearIsFirst = true;
              s1 = s.substring(0, 5);
              s2 = s.substring(5);
          }
          else {
              s1 = s.substring(0, i).trim();
              s2 = s.substring(i + 1, s.length()).trim();
              // now it is trickier to determine if the month or year is first
              Year y1 = Month.evaluateAsYear(s1);
              if (y1 == null) {
                  yearIsFirst = false;
              }
              else {
                  Year y2 = Month.evaluateAsYear(s2);
                  if (y2 == null) {
                      yearIsFirst = true;
                  }
                  else {
                      yearIsFirst = (s1.length() > s2.length());
                  }
              }
          }
          Year year;
          int month;
          if (yearIsFirst) {
              year = Month.evaluateAsYear(s1);
              month = SerialDate.stringToMonthCode(s2);
          }
          else {
              year = Month.evaluateAsYear(s2);
              month = SerialDate.stringToMonthCode(s1);
          }
          if (month == -1) {
              throw new TimePeriodFormatException("Can't evaluate the month.");
          }
          if (year == null) {
              throw new TimePeriodFormatException("Can't evaluate the year.");
          }
          result = new Month(month, year);
          return result;
      }
  
      /**
       * Finds the first occurrence of '-', or if that character is not found,
       * the first occurrence of ',', or the first occurrence of ' ' or '.'
       *
       * @param s  the string to parse.
       *
       * @return The position of the separator character, or <code>-1</code> if
       *     none of the characters were found.
       */
      private static int findSeparator(String s) {
          int result = s.indexOf('-');
          if (result == -1) {
              result = s.indexOf(',');
          }
          if (result == -1) {
              result = s.indexOf(' ');
          }
          if (result == -1) {
              result = s.indexOf('.');
          }
          return result;
      }
  
      /**
       * Creates a year from a string, or returns <code>null</code> (format
       * exceptions suppressed).
       *
       * @param s  the string to parse.
       *
       * @return <code>null</code> if the string is not parseable, the year
       *         otherwise.
       */
      private static Year evaluateAsYear(String s) {
          Year result = null;
          try {
              result = Year.parseYear(s);
          }
          catch (TimePeriodFormatException e) {
              // suppress
          }
          return result;
      }
  
  }
  